We are currently experiencing a critical issue with an ADcmXL3021 device (part number: ADcmXL3021BZ) related to RTS mode and SPI access lockout.
During our configuration process, the device was placed into RTS mode (REC_CTRL = 0x0003) and this configuration was saved to flash. However, the MISC_CTRL[12] bit was not set prior to saving, meaning the SYNC/RTS pin was not enabled. As a result, after any hardware reset, the device immediately starts in RTS mode and SPI communication is completely locked out.
We have confirmed the following:
- The SYNC/RTS pin is physically connected and functional on our hardware, but is ignored due to MISC_CTRL[12] = 0.
- All attempts to regain SPI access through SYNC LOW + RST cycling have failed.
- We are unable to issue any SPI commands, including GLOB_CMD, to recover or overwrite the flash contents.
- This appears to match the “permanent RTS lockout” condition described in your documentation and user forums.
- Spi communication clock speed is 1.56 Mhz in all test processes. Cannot be increased due to hardware limitations. Communication attempts were made at the specified speed for communication tests in sections where the BUSY pin was HIGH.
*We would like to request one of the following:*
1. A factory reset or reprogramming procedure to erase the user flash contents and restore default settings.
2. If not available, information on how to return the part for reprogramming or replacement.
We kindly ask for your support in recovering this part. Please let us know the proper RMA procedure if applicable, and whether there is any in-field JTAG or programming tool available to perform a flash erase operation on this device.
Thank you in advance for your help
